ABSTRACT
AIM: To investigate the effect of endoplasmic reticulum stress pathway on the apoptosis of tongue squamous cancer Tca8113 cells induced by antitumor component-I from Agkistrodon acutus venom (AAVC-I). METHODS: The in vitro experiments were performed on subculture tongue squamous cancer Tca8113 cells in their growth period. A normal control group, a DL-dithiothreitol (DTT) positive control group and different AAVC-I concentrations were set according to the experiment objective. MTT assay was used to detect the proliferation inhibition of Tca8113 cells after been treated with different concentrations of DTT and AAVC-I for 24 h. The results were used to choose appropriate concentrations of DTT and AAVC-I in DTT positive control group and AAVC-I treated group, respectively. HE staining and Annexin V-FITC/PI double fluorescence staining were used to monitor the apoptosis of Tca8113 cells. Western blot was used to identify the expression levels of apoptosis-related proteins including endoplasmic reticulum stress glucose-regulatory protein 78 (GRP78), enhance-binding protein-homologousprotein (CHOP), cysteine-containing aspartate specific protease-12 (Caspase-12), cysteine-containing aspartate specific protease-9 (Caspase-9) and cysteine-containing aspartate specific protease-3 (Caspase-3).RESULTS:The proliferation inhibition of Tca8113 cells increased with an increased concentration of AAVC-I concentration (P<0.05), causing cell shrinkage, increased cell gaps, cytonuclear condensation, cell fragmentation, the appearance of apoptotic bodies, and increased rate of apoptosis (P<0.05). In addition, the expression level of GRP78 protein, CHOP protein, proteins of Caspase-12, Caspase-9 and Caspase-3 were increased (P<0.05).CONCLUSION: Endoplasmic reticulum stress CHOP/Caspase-12 pathway plays an important role in AAVC-I induced Tca8113 cells apoptosis.
ABSTRACT
Objective This study aims to investigate the effect of geranylgeranyltransferaseⅠ (GGTase-Ⅰ) on the proliferation and growth of tongue squamous cancer cells. Methods Three small interfering RNAs (siRNAs) were designed on the basis of the GGTase-Ⅰ sequence in GeneBank. These siRNAs were then transfected into tongue squamous cancer cells Cal-27. The mRNA and protein expression of GGTase-Ⅰ and RhoA were examined by real-time quantitative polymerase chain reaction and Western blotting, respectively. The expression of Cyclin D1 and p21 were examined by Western blotting. The proliferation and growth ability were analyzed by cell counting kit-8 assay and flow cytometry. Results The mRNA and protein expression of GGTase-Ⅰ in Cal-27 was reduced significantly after the GGTase-Ⅰ siRNAs were transfected (P<0.05). No significant difference in RhoA mRNA and protein expression was detected (P>0.05). Cyclin D1 expression decreased, whereas p21 expression increased significantly. The cell cycle was altered, and the growth-proliferative activity was inhibited (P<0.05). Conclusion GGTase-Ⅰ siRNA can inhibit the expression of GGTase-Ⅰ and the proliferative activity of tongue squamous cancer cells. GGTase-Ⅰ may be a potential target for gene therapy in tongue squamous cell cancer.
ABSTRACT
<p><b>OBJECTIVE</b>RNA interference was used to silence geranylgeranyltransferase Ⅰ(GGTase-Ⅰ) in vitro and to study the effect of GGTase-Ⅰ on the migration and invasion of tongue squamous cancer cells.</p><p><b>METHODS</b>Three small interfering RNAs (siRNA) were designed according to the GGTase-Ⅰ sequence by Genebank and were transfected into tongue squamous cancer cells Cal-27 to knock down GGTase-Ⅰ expression. The tested cells were divided into three groups, as follows: the RNA-interfered groups (GGTase-Ⅰ siRNA1, GGTase-Ⅰ siRNA 2, GGTase-Ⅰ siRNA 3), a negative control group (disrupted by random sequence NC-siRNA), and a blank control group. GGTase-Ⅰ and RhoA gene expressions were examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. The optimum interference group was screened by qRT-PCR and Western blot and was assigned as the experimental group. Matrix metalloproteinase (MMP)-2 and MMP-9 protein expressions were examined by Western blot. GTP-RhoA expression of protein was examined by GST-pull down. The migration and invasion abilities were analyzed by wound healing assay and Transwell motility assay.</p><p><b>RESULTS</b>GGTase-Ⅰ mRNA and protein expression in Cal-27 decreased significantly after transfection of GGTase-I siRNA (P<0.05). No significant difference of RhoA gene expression was detected. MMP-2, MMP-9, and GTP-RhoA protein expressions decreased significantly (P<0.05). The migration and invasion abilities were inhibited (P<0.05).</p><p><b>CONCLUSIONS</b>To inhibit GGTase-Ⅰ expression, the migration and invasion abilities of tongue squamous cancer cells should also be inhibited. Further studies on GGTase-Ⅰ may provide novel effective molecular targets for tongue squamous cancer cells.</p>